Improvement in apparatus for leaching bark



UNITED STATES PATENT OFFICE.

HILEN C. GROW'ELL, OF MORGAN, OHIO.

IMPROVVEMENT IN APPARATUS FOR LEACHING BARK, 80C.

Specification forming part of Letters Patent No. 111,730, dated February14, 1871.

To all whom it may concern.'

Be it known that I, HILEN C. GRoWELL, of Morgan, in the county ofAshtabula and State of Ohio, have invented a new and useful Improvementin Iieaching Apparatus 5 and I do hereby declare that the following is afull, clear, and exact description thereof, which will enable othersskilled in the art to make and use the same, reference being had to theaccompanying drawings, forming part of this specilication.

This invention relates to improvements in leaching apparatus, andconsists in the construction and arrangement ot' a steam-pipe, hollowvertical standard with a revolving top and a perforated false bottom, ashereinafter described, whereby a circulation ot' the tanning liquid maybe maintained in the tank,

from all sides to the center thereof, by the introduction or injectionof steam.

In the accompanying drawings, Figure lrep resents a vertical section ofthe apparatus on the line a: .fr of Fig. 2. Fig. 2 is a top or planview.

Similar letters of reference indicate corresponding parts.

Ais a leach or tank of anydesired shape and size.

B is a false bottom, which is raised from the true bottom on timbers,which are seen in dotted lines in Fig. 2. On the under side of thesetimbers notches or recesses C are cut, so that the liquid can readilyilow beneath them. The false bottom B is suciently open to allow theliquid to pass up or down through it.

D is a steampipe, which connects with a steam-boiler. It passes downfrom the top of the leach into the space beneath the false bottom andenters the large base-tube E, wh'ich rests on the true bottom of theleach. This base-tube has apertures through it near its lower end,through which the liquor flows freely;

F is a tube ofsmaller diameter than E, which screws into E, as seen atG, and extends up with achamber, H, upon its upper end.1 This chamberreceives the short tube I, which tube is allowed to turn er revolve inthe chamber. The tube I may be curved so as to give the liquor a lateraldirection and be made to revolve by the reaction ofthe liquid againstthe atmospher, and thus distribute the liquor evenly over the leach; butI prefer another arrangement. On the end of this short tube is arevolving wheel, J. This wheel has curved orifices radiating from itscenter, and so arranged that it is made to revolve by the pressure ofthe liquid against the atmosphere, or upon the principle of the Barkermill. This wheel may be made to revolve either a little above or alittle below the surface of the liquid in the leach.

The tan-bark or other article which it may be desired to leach is placedupon the false bottom, the leach being tilled about two-thirds full.Water is then added until the waterline K (or thereabout) is reached.Steam is then let into the pipe I), which, meeting with water in thebase-tube E, forces the water up through the tube F and out through therevolving wheel J, discharging the liquid upon or near the surface. Theliquorcondenses the steam, by which it is forced up, and consequentlyabsorbs its heat, the steam thus heating` the liquid while keeping upaconstant circulation through the bark. The result of this circulation,is the sediment, gum, and resin ot' the bark are constantly beingcarried up and deposited on the top of the bark. The liquor, beingconstantly descending through the bark, serves to keep the bark 'downupon the false bottom, thus keeping all the bark under the liquor, sothat it is all evenly heat-ed and leached. By this means the liquor ismade to extract all the tannin ot' the bark, and can be made as strongor concentrated as may he desired.

No other process or apparatus with which I am acquainted extracts somuch tannin t'rom bark as this.

By this apparatus no gum is left in` the liquor to fill up the pores ot'the hide. Consequently the liquor penetrates the hide much more readily,thereby saving nearly or quite one-third of the time usually employed intanning. The liquor being pure, the result is that the leather' is softand pliable, of lighter color, and generally' of better quality than ismade in the ordinary way.

Having thus described my invention, I claim as new and desire to secureby Letters Patent- The steam-pipe D, laterally-perforated base- E, tubeF, having the revolving top J and the false slotted bottom B, allconstructed and arranged as shown and described, for the purposespeciied.

HILEN O.. GROWELL.

Witnesses:

M. BEETTELL, A. C. WILooX.

